Which benzodiazepine has the shortest half-life among the listed agents?

• A. Flumazenil
• B. Midazolam
• C. Diazepam
• D. Lorazepam

Answer: (A)

Understanding half-life helps explain why one agent clears fastest. Flumazenil, a benzodiazepine receptor antagonist used to reverse sedation, is cleared very quickly, with an elimination half-life of roughly 0.7 to 1.3 hours. That is much shorter than the other listed benzodiazepines: midazolam typically has a half-life around 1.5–2.5 hours (though it can vary with infusion), while diazepam runs about 20–50 hours and lorazepam about 10–20 hours due to differences in metabolism and active metabolites. Because of this rapid clearance, flumazenil has the shortest half-life among these agents. Note that flumazenil is not a benzodiazepine itself but a receptor antagonist that reverses benzodiazepine effects.